Phonegap: Storing JSON Data into SQLite using Ajax

i am trying to store the json data into SQLite using Ajax. Here's my code :

var db = window.openDatabase("Pemda", "1.0", "Database Pemda", 200000);

db.transaction(populateDB, errorCB, successCB);

function populateDB(tx) {
tx.executeSql('DROP TABLE IF EXISTS PEMDA2');
tx.executeSql('CREATE TABLE IF NOT EXISTS PEMDA2 (id unique, name)');
$.ajax({
  url: "http://ift.tt/1ypHmim",
  dataType: "json",
  success: function(parsed_json898) {
    $.each(parsed_json898, function(x,item){
      myname = item.name;
      myid = item.id;
      tx.executeSql('INSERT INTO PEMDA2 (id, name) VALUES ('+myid+', "'+myname+'")');
   });
},
timeout: 30000,   
error:function(){ 
   alert("Error");
}  
});
}

But, the code gives the error : Uncaught InvalidStateError: An attempt was made to use an object that is not, or is no longer, usable

How to fix this ? Thanks for your help.